BSD 4_3_Net_1 release

[unix-history] / talk / io.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
static char sccsid[] = "@(#)io.c        5.3 (Berkeley) 6/29/88";
#endif /* not lint */

/*
* This file contains the I/O handling and the exchange of 
* edit characters. This connection itself is established in
* ctl.c
*/

#include "talk.h"
#include <stdio.h>
#include <errno.h>
#include <sys/time.h>

#define A_LONG_TIME 10000000
#define STDIN_MASK (1<<fileno(stdin))   /* the bit mask for standard
                                          input */
extern int errno;

/*
* The routine to do the actual talking
*/
talk()
{
       register int read_template, sockt_mask;
       int read_set, nb;
       char buf[BUFSIZ];
       struct timeval wait;

       message("Connection established\007\007\007");
       current_line = 0;
       sockt_mask = (1<<sockt);

       /*
        * Wait on both the other process (sockt_mask) and 
        * standard input ( STDIN_MASK )
        */
       read_template = sockt_mask | STDIN_MASK;
       forever {
               read_set = read_template;
               wait.tv_sec = A_LONG_TIME;
               wait.tv_usec = 0;
               nb = select(32, &read_set, 0, 0, &wait);
               if (nb <= 0) {
                       if (errno == EINTR) {
                               read_set = read_template;
                               continue;
                       }
                       /* panic, we don't know what happened */
                       p_error("Unexpected error from select");
                       quit();
               }
               if (read_set & sockt_mask) { 
                       /* There is data on sockt */
                       nb = read(sockt, buf, sizeof buf);
                       if (nb <= 0) {
                               message("Connection closed. Exiting");
                               quit();
                       }
                       display(&his_win, buf, nb);
               }
               if (read_set & STDIN_MASK) {
                       /*
                        * We can't make the tty non_blocking, because
                        * curses's output routines would screw up
                        */
                       ioctl(0, FIONREAD, (struct sgttyb *) &nb);
                       nb = read(0, buf, nb);
                       display(&my_win, buf, nb);
                       /* might lose data here because sockt is non-blocking */
                       write(sockt, buf, nb);
               }
       }
}

extern  int errno;
extern  int sys_nerr;
extern  char *sys_errlist[];

/*
* p_error prints the system error message on the standard location
* on the screen and then exits. (i.e. a curses version of perror)
*/
p_error(string) 
       char *string;
{
       char *sys;

       sys = "Unknown error";
       if (errno < sys_nerr)
               sys = sys_errlist[errno];
       wmove(my_win.x_win, current_line%my_win.x_nlines, 0);
       wprintw(my_win.x_win, "[%s : %s (%d)]\n", string, sys, errno);
       wrefresh(my_win.x_win);
       move(LINES-1, 0);
       refresh();
       quit();
}

/*
* Display string in the standard location
*/
message(string)
       char *string;
{

       wmove(my_win.x_win, current_line%my_win.x_nlines, 0);
       wprintw(my_win.x_win, "[%s]\n", string);
       wrefresh(my_win.x_win);
}